Organic electroluminescent device

ABSTRACT

The present disclosure relates to an organic electroluminescent device. The organic electroluminescent device of the present disclosure shows high luminous efficiency and good lifespan by comprising a specific combination of the plural kinds of host compounds and a specific hole transport compound.

TECHNICAL FIELD

The present disclosure relates to an organic electroluminescent device.

BACKGROUND ART

An electroluminescent (EL) device is a self-light-emitting device whichhas advantages in that it provides a wider viewing angle, a greatercontrast ratio, and a faster response time. An organic EL device wasfirst developed by Eastman Kodak, by using small aromatic diaminemolecules and aluminum complexes as materials to form a light-emittinglayer [Appl. Phys. Lett. 51, 913, 1987].

The organic EL device converts electric energy into light whenelectricity is applied to an organic light-emitting material(s).Generally, the organic EL device has a structure comprising an anode, acathode, and an organic layer disposed between the anode and thecathode. The organic layer of the organic EL device comprises a holeinjection layer, a hole transport layer, an electron blocking layer, alight-emitting layer (comprising a host material and a dopant material),an electron buffering layer, a hole blocking layer, an electrontransport layer, an electron injection layer, etc. Depending on itsfunction, materials for forming the organic layer can be classified as ahole injection material, a hole transport material, an electron blockingmaterial, a light-emitting material, an electron buffering material, ahole blocking material, an electron transport material, an electroninjection material, etc. When a voltage is applied to the organic ELdevice, holes and electrons are injected from an anode and a cathode,respectively, to the light-emitting layer. Excitons having high energyare formed by recombinations between the holes and the electrons. Theenergy of excitons puts the light-emitting organic compound in anexcited state, and the decay of the excited state results in arelaxation of the energy level into a ground state, accompanied bylight-emission.

The most important factor determining luminous efficiency in the organicEL device is light-emitting materials. The light-emitting material needsto have high quantum efficiency, high electron mobility, and high holemobility. Furthermore, the light-emitting layer formed by thelight-emitting material needs to be uniform and stable. Depending oncolors visualized by light-emission, the light-emitting materials can beclassified as a blue-, green-, or red-emitting material, and a yellow-or orange-emitting material can be additionally included therein.Depending on its function, the light-emitting materials can beclassified as a host material and a dopant material. Recently, thedevelopment of an organic EL device providing high efficiency and longlifespan is an urgent issue. Particularly, considering EL characteristicrequirements for a middle or large-sized panel of OLED, materialsshowing better characteristics than conventional ones must be urgentlydeveloped. The host material acts as a solvent in a solid state andtransfers energy, and thus needs to have high purity and a molecularweight appropriate for vacuum deposition. Furthermore, the host materialneeds to have high glass transition temperature and high thermaldegradation temperature to achieve thermal stability, highelectro-chemical stability to achieve long lifespan, easiness of formingamorphous thin film, good adhesion to materials of adjacent layers, andnon-migration to other layers.

In order to enhance color purity, luminous efficiency and stability, thelight-emitting material may be used as a mixture of a host and a dopant.Generally, devices showing good electroluminescent characteristicscomprise a light-emitting layer in which a dopant is doped into a host.In the dopant/host material system, efficiencies and lifespan of thedevice are highly affected by the host material, and thus selection ofthe host material is important.

WO 2013/168688 A1, WO 2009/060757 A1, and Japanese Patent ApplicationLaying-Open No. 2013-183036 A1 disclose an organic electroluminescentdevice in which a biscarbazole derivative is employed as a hostmaterial. However, the references fail to specifically disclose anorganic electroluminescent device employing the following compounds: asa plurality of hosts, a biscarbazole derivative in which the nitrogenatoms of carbazoles are linked to aryls, respectively, and a carbazolederivative in which the nitrogen atom of carbazole is linked to anitrogen-containing heteroaryl; and as a hole transport compound, afluorene or spirobifluorene derivative which is linked to a diarylamino.

DISCLOSURE OF INVENTION Technical Problem

The object of the present disclosure is to provide an organicelectroluminescent device having high efficiency and long lifespan.

Solution to Problems

The present inventors found that the above object can be achieved by anorganic electroluminescent device comprising an anode, a cathode, and anorganic layer between the anode and the cathode, wherein the organiclayer comprises one or more light-emitting layers and one or more holetransport layers; at least one of the one or more light-emitting layerscomprises one or more dopant compounds and two or more host compounds; afirst host compound of the two or more host compounds is represented bythe following formula 1; a second host compound is represented by thefollowing formula 2; and at least one of the one or more hole transportlayers comprises the compound represented by the following formula 3:

wherein

A₁ and A₂, each independently, represent a substituted or unsubstituted(C6-C30)aryl, provided that a nitrogen-containing heteroaryl is excludedfrom the substituent for A₁ and A₂;

L₁ represents a single bond or a substituted or unsubstituted(C6-C30)arylene;

X₁ to X₁₆, each independently, represent hydrogen, deuterium, a halogen,a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted orunsubstituted (C2-C30)alkenyl, a substituted or unsubstituted(C2-C30)alkynyl, a substituted or unsubstituted (C3-C30)cycloalkyl, asubstituted or unsubstituted (C6-C60)aryl, a substituted orunsubstituted 3- to 30-membered heteroaryl, a substituted orunsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstitutedtri(C6-C30)arylsilyl, a substituted or unsubstituteddi(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted(C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstitutedmono- or di-(C6-C30)arylamino; or may be linked to an adjacentsubstituent(s) to form a substituted or unsubstituted (C3-C30), mono- orpolycyclic, alicyclic or aromatic ring, whose carbon atom(s) may bereplaced with at least one hetero atom selected from nitrogen, oxygen,and sulfur;

wherein

Ma represents a substituted or unsubstituted nitrogen-containing 5- to11-membered heteroaryl;

La represents a single bond, or a substituted or unsubstituted(C6-C30)arylene;

Xa to Xh, each independently, represent hydrogen, deuterium, a halogen,a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted orunsubstituted (C2-C30)alkenyl, a substituted or unsubstituted(C2-C30)alkynyl, a substituted or unsubstituted (C3-C30)cycloalkyl, asubstituted or unsubstituted (C6-C60)aryl, a substituted orunsubstituted 3- to 30-membered heteroaryl, a substituted orunsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstitutedtri(C6-C30)arylsilyl, a substituted or unsubstituteddi(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted(C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstitutedmono- or di-(C6-C30)arylamino; or may be linked to an adjacentsubstituent(s) to form a substituted or unsubstituted (C3-C30), mono- orpolycyclic, alicyclic or aromatic ring, whose carbon atom(s) may bereplaced with at least one hetero atom selected from nitrogen, oxygen,and sulfur;

wherein

A₄ and A₅, each independently, represent a substituted or unsubstituted(C6-C30)aryl;

L₃ represents a single bond or a substituted or unsubstituted(C6-C30)arylene;

Z₁ to Z₉, each independently, represent hydrogen, deuterium, a halogen,a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted orunsubstituted (C2-C30)alkenyl, a substituted or unsubstituted(C2-C30)alkynyl, a substituted or unsubstituted (C3-C30)cycloalkyl, asubstituted or unsubstituted (C6-C60)aryl, a substituted orunsubstituted 3- to 30-membered heteroaryl, a substituted orunsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstitutedtri(C6-C30)arylsilyl, a substituted or unsubstituteddi(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted(C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstitutedmono- or di-(C6-C30)arylamino; or may be linked to an adjacentsubstituent(s) to form a substituted or unsubstituted (C3-C30), mono- orpolycyclic, alicyclic or aromatic ring, whose carbon atom(s) may bereplaced with at least one hetero atom selected from nitrogen, oxygen,and sulfur;

n represents an integer of 0 or 1;

t represents an integer of 0, 1, or 2; and

the heteroaryl contains at least one hetero atom selected from B, N, O,S, Si, and P.

Advantageous Effects of Invention

An organic electroluminescent device of the present disclosure has highefficiencies and long lifespan. A display system or lighting systemusing the organic electroluminescent device can be manufactured.

MODE FOR THE INVENTION

Hereinafter, the present disclosure will be described in detail.However, the following description is intended to explain the invention,and is not meant in any way to restrict the scope of the invention.

The details of the organic electroluminescent device of the presentdisclosure are as follows.

According to one embodiment of the organic electroluminescent device ofthe present disclosure, the compound of formula 1 may be represented bythe following formula 5, 6, 7, or 8.

wherein, A₁, A₂, L₁ and X₁ to X₁₆ are as defined in formula 1.

In formula 1, A₁ and A₂, each independently, represent a substituted orunsubstituted (C6-C30)aryl. A₁ and A₂, each independently, may representpreferably, a substituted or unsubstituted (C6-C18)aryl; and morepreferably, a (C6-C18)aryl unsubstituted or substituted with a cyano, ahalogen, a (C1-C6)alkyl, a (C6-C12)aryl, or a tri(C6-C12)arylsilyl.Specifically, A₁ and A₂, each independently, may be selected from thegroup consisting of a substituted or unsubstituted phenyl, a substitutedor unsubstituted biphenyl, a substituted or unsubstituted terphenyl, asubstituted or unsubstituted naphthyl, a substituted or unsubstitutedfluorenyl, a substituted or unsubstituted benzofluorenyl, a substitutedor unsubstituted phenanthrenyl, a substituted or unsubstitutedanthracenyl, a substituted or unsubstituted indenyl, a substituted orunsubstituted triphenylenyl, a substituted or unsubstituted pyrenyl, asubstituted or unsubstituted tetracenyl, a substituted or unsubstitutedperylenyl, a substituted or unsubstituted chrysenyl, a substituted orunsubstituted phenylnaphthyl, a substituted or unsubstitutednaphthylphenyl, and a substituted or unsubstituted fluoranthenyl.Herein, the substituent for the substituted phenyl, etc. may be a cyano,a halogen, a (C1-C6)alkyl, a (C6-C12)aryl, or a tri(C6-C12)arylsilyl. A₁and A₂ may be the same or different.

In formula 1, X₁ to X₁₆, each independently, represent hydrogen,deuterium, a halogen, a cyano, a substituted or unsubstituted(C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, asubstituted or unsubstituted (C2-C30)alkynyl, a substituted orunsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted(C6-C60)aryl, a substituted or unsubstituted 3- to 30-memberedheteroaryl, a substituted or unsubstituted tri(C1-C30)alkylsilyl, asubstituted or unsubstituted tri(C6-C30)arylsilyl, a substituted orunsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted orunsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted orunsubstituted mono- or di-(C6-C30)arylamino; or may be linked to anadjacent substituent(s) to form a substituted or unsubstituted (C3-C30),mono- or polycyclic, alicyclic or aromatic ring, whose carbon atom(s)may be replaced with at least one hetero atom selected from nitrogen,oxygen, and sulfur. X₁ to X₁₆, each independently, may representpreferably, hydrogen, a cyano, a substituted or unsubstituted(C1-C10)alkyl, a substituted or unsubstituted (C6-C20)aryl, asubstituted or unsubstituted 5- to 20-membered heteroaryl, or asubstituted or unsubstituted tri(C6-C12)arylsilyl; and more preferably,hydrogen, a cyano, a (C1-C10)alkyl, a (C6-C20)aryl unsubstituted orsubstituted with a cyano, a (C1-C10)alkyl, or a tri(C6-C12)arylsilyl, a5- to 20-membered heteroaryl unsubstituted or substituted with a(C1-C10)alkyl, a (C6-C15)aryl, or a tri(C6-C12)arylsilyl, or atri(C6-C12)arylsilyl unsubstituted or substituted with a (C1-C10)alkyl.Specifically, X₁ to X₁₆, each independently, may represent hydrogen; acyano; a (C1-C6)alkyl; phenyl, biphenyl, terphenyl, or naphthyl,unsubstituted or substituted with a cyano, a (C1-C6)alkyl, ortriphenylsilyl; dibenzothiophene or dibenzofuran, unsubstituted orsubstituted with a (C1-C6)alkyl, phenyl, biphenyl, naphthyl, ortriphenylsilyl; or triphenylsilyl unsubstituted or substituted with a(C1-C6)alkyl.

In formula 1, L₁ represents a single bond, or a substituted orunsubstituted (C6-C30)arylene. Preferably, L₁ may represent a singlebond, or a substituted or unsubstituted (C6-C15)arylene.

L₁ may represent a single bond, or one selected from the followingformulae 9 to 21.

wherein

Xi to Xp, each independently, represent hydrogen, deuterium, a halogen,a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted orunsubstituted (C2-C30)alkenyl, a substituted or unsubstituted(C2-C30)alkynyl, a substituted or unsubstituted (C3-C30)cycloalkyl, asubstituted or unsubstituted (C6-C60)aryl, a substituted orunsubstituted 3- to 30-membered heteroaryl, a substituted orunsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstitutedtri(C6-C30)arylsilyl, a substituted or unsubstituteddi(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted(C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstitutedmono- or di-(C6-C30)arylamino; or may be linked to an adjacentsubstituent(s) to form a substituted or unsubstituted (C3-C30), mono- orpolycyclic, alicyclic or aromatic ring, whose carbon atom(s) may bereplaced with at least one hetero atom selected from nitrogen, oxygen,and sulfur; and

represents a bonding site.

Xi to Xp, each independently, may represent preferably, hydrogen, ahalogen, a cyano, a (C1-C10)alkyl, a (C3-C20)cycloalkyl, a (C6-C12)aryl,a (C1-C6)alkyldi(C6-C12)arylsilyl, or a tri(C6-C12)arylsilyl; and morepreferably, hydrogen, a cyano, a (C1-C6)alkyl, or atri(C6-C12)arylsilyl.

In formula 2, Ma represents a substituted or unsubstitutednitrogen-containing 5- to 11-membered heteroaryl. Ma may representpreferably, a substituted or unsubstituted nitrogen-containing 6- to10-membered heteroaryl. Ma may represent more preferably, anitrogen-containing 6- to 10-membered heteroaryl substituted with thefollowing: an unsubstituted (C6-C18)aryl; a (C6-C12)aryl substitutedwith a cyano; a (C6-C12)aryl substituted with a (C1-C6)alkyl; a(C6-C12)aryl substituted with a tri(C6-C12)arylsilyl; or a 6- to15-membered heteroaryl.

Specifically, Ma may represent a substituted or unsubstituted monocyclicring-type heteroaryl selected from the group consisting of a substitutedor unsubstituted pyrrolyl, a substituted or unsubstituted imidazolyl, asubstituted or unsubstituted pyrazolyl, a substituted or unsubstitutedtriazinyl, a substituted or unsubstituted tetrazinyl, a substituted orunsubstituted triazolyl, a substituted or unsubstituted tetrazolyl, asubstituted or unsubstituted pyridyl, a substituted or unsubstitutedpyrazinyl, a substituted or unsubstituted pyrimidinyl, and a substitutedor unsubstituted pyridazinyl, or a substituted or unsubstituted fusedring-type heteroaryl selected from the group consisting of a substitutedor unsubstituted benzimidazolyl, a substituted or unsubstitutedisoindolyl, a substituted or unsubstituted indolyl, a substituted orunsubstituted indazolyl, a substituted or unsubstitutedbenzothiadiazolyl, a substituted or unsubstituted quinolyl, asubstituted or unsubstituted isoquinolyl, a substituted or unsubstitutedcinnolinyl, a substituted or unsubstituted quinazolinyl, a substitutedor unsubstituted naphthyridinyl, and a substituted or unsubstitutedquinoxalinyl. Preferably, Ma may represent a substituted orunsubstituted triazinyl, a substituted or unsubstituted pyrimidinyl, asubstituted or unsubstituted pyridyl, a substituted or unsubstitutedquinolyl, a substituted or unsubstituted isoquinolyl, a substituted orunsubstituted quinazolinyl, a substituted or unsubstitutednaphthyridinyl, or a substituted or unsubstituted quinoxalinyl. Thesubstituent for the substituted pyrrolyl, etc. of Ma may be selectedfrom a (C6-C18)aryl, a (C6-C12)aryl substituted with a cyano, a(C6-C12)aryl substituted with a (C1-C6)alkyl, a (C6-C12)aryl substitutedwith a tri(C6-C12)arylsilyl, a cyano, a (C1-C6)alkyl, atri(C6-C12)arylsilyl, or a 6- to 15-membered heteroaryl. Specifically,the substituent may be selected from phenyl, biphenyl, terphenyl,naphthyl, phenylnaphthyl, naphthylphenyl, phenanthrenyl, anthracenyl,dibenzothiophenyl, or dibenzofuranyl, unsubstituted or substituted witha cyano, a (C1-C6)alkyl, or triphenylsilyl.

In formula 2, La represents a single bond, or a substituted orunsubstituted (C6-C30)arylene. Preferably, La may represent a singlebond, or a substituted or unsubstituted (C6-C12)arylene. Specifically,La may represent a single bond, or one of formulae 9 to 21.

In formula 2, Xa to Xh, each independently, represent hydrogen,deuterium, a halogen, a cyano, a substituted or unsubstituted(C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, asubstituted or unsubstituted (C2-C30)alkynyl, a substituted orunsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted(C6-C60)aryl, a substituted or unsubstituted 3- to 30-memberedheteroaryl, a substituted or unsubstituted tri(C1-C30)alkylsilyl, asubstituted or unsubstituted tri(C6-C30)arylsilyl, a substituted orunsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted orunsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted orunsubstituted mono- or di-(C6-C30)arylamino, or may be linked to anadjacent substituent(s) to form a substituted or unsubstituted (C3-C30),mono- or polycyclic, alicyclic or aromatic ring, whose carbon atom(s)may be replaced with at least one hetero atom selected from nitrogen,oxygen, and sulfur. Preferably, Xa to Xh, each independently, mayrepresent hydrogen, a cyano, a substituted or unsubstituted(C6-C15)aryl, a substituted or unsubstituted 10- to 20-memberedheteroaryl, or a substituted or unsubstituted tri(C6-C10)arylsilyl, ormay be linked to an adjacent substituent(s) to form a substituted orunsubstituted (C6-C20), mono- or polycyclic aromatic ring, whose carbonatom(s) may be replaced with at least one hetero atom selected fromnitrogen, oxygen, and sulfur. More preferably, Xa to Xh, eachindependently, may represent hydrogen, a cyano, a (C6-C15)arylunsubstituted or substituted with a tri(C6-C10)arylsilyl, or a 10- to20-membered heteroaryl unsubstituted or substituted with a (C6-C12)aryl;or may be linked to an adjacent substituent(s) to form a substituted orunsubstituted benzene, a substituted or unsubstituted indole, asubstituted or unsubstituted benzindole, a substituted or unsubstitutedindene, a substituted or unsubstituted benzofuran, or a substituted orunsubstituted benzothiophene.

In formula 3, A₄ and A₅, each independently, represent a substituted orunsubstituted (C6-C30)aryl. Specifically, A₄ and A₅, each independently,may be selected from the group consisting of a substituted orunsubstituted phenyl, a substituted or unsubstituted biphenyl, asubstituted or unsubstituted terphenyl, a substituted or unsubstitutednaphthyl, a substituted or unsubstituted phenanthrenyl, a substituted orunsubstituted anthracenyl, a substituted or unsubstituted pyrenyl, asubstituted or unsubstituted tetracenyl, a substituted or unsubstitutedchrysenyl, a substituted or unsubstituted fluorenyl, a substituted orunsubstituted benzofluorenyl, a substituted or unsubstitutedfluoranthenyl, a substituted or unsubstituted triphenylenyl, and asubstituted or unsubstituted spirobifluorenyl. Specifically, thesubstituent for the substituted aryl such as the substituted phenyl ofA₄ and A₅ may be selected from a (C1-C10)alkyl, a cyano, a halogen, a(C6-C18)aryl, or a 6- to 18-membered heteroaryl; and more specifically,a (C1-C6)alkyl, a cyano, a halogen, phenyl, biphenyl, terphenyl,naphthyl, phenanthrenyl, anthracenyl, pyrenyl, tetracenyl, chrysenyl,fluorenyl, fluorenyl substituted with two (2) methyl groups, fluorenylsubstituted with two (2) phenyl groups, fluorenyl substituted with amethyl group and a phenyl group, dibenzothiophenyl, dibenzofuranyl, orcarbazolyl. A₄ and A₅ may be the same or different.

In formula 3, L₃ represents a single bond, or a substituted orunsubstituted (C6-C30)arylene; preferably, a single bond, or asubstituted or unsubstituted (C6-C18)arylene; and more preferably, asingle bond, or a (C6-C18)arylene unsubstituted or substituted with a(C1-C6)alkyl or phenyl. Specifically, L₃ may represent a single bond orphenyl.

In formula 3, Z₁ to Z₉, each independently, represent hydrogen,deuterium, a halogen, a cyano, a substituted or unsubstituted(C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, asubstituted or unsubstituted (C2-C30)alkynyl, a substituted orunsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted(C6-C60)aryl, a substituted or unsubstituted 3- to 30-memberedheteroaryl, a substituted or unsubstituted tri(C1-C30)alkylsilyl, asubstituted or unsubstituted tri(C6-C30)arylsilyl, a substituted orunsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted orunsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted orunsubstituted mono- or di-(C6-C30)arylamino, or may be linked to anadjacent substituent(s) to form a substituted or unsubstituted (C3-C30),mono- or polycyclic, alicyclic or aromatic ring, whose carbon atom(s)may be replaced with at least one hetero atom selected from nitrogen,oxygen, and sulfur. Preferably, Z₁ to Z₉, each independently, mayrepresent hydrogen, deuterium, a halogen, a cyano, a substituted orunsubstituted (C1-C30)alkyl, a substituted or unsubstituted(C6-C30)aryl, a substituted or unsubstituted 6- to 30-memberedheteroaryl, or a substituted or unsubstituted mono- ordi-(C6-C30)arylamino; or one to three pairs selected from Z₁ and Z₂, Z₂and Z₃, Z₄ and Z₅, Z₅ and Z₆, Z₇ and Z₈, and Z₈ and Z₉, as a pair ofadjacent substituents, may form a substituted or unsubstituted (C3-C30),mono- or polycyclic aromatic ring, whose carbon atom(s) may be replacedwith one to three hetero atoms selected from nitrogen, oxygen, andsulfur. Specifically, Z₁ to Z₉, each independently, may representhydrogen, a (C1-C6)alkyl, or a mono- or di-(C6-C18)arylamino; or one totwo pairs selected from Z₁ and Z₂, Z₂ and Z₃, Z₄ and Z₅, Z₅ and Z₆, Z₇and Z₈, and Z₈ and Z₉, as a pair of adjacent substituents, may form asubstituted or unsubstituted benzene, a substituted or unsubstitutedindene, a substituted or unsubstituted cyclopentanaphthalene, asubstituted or unsubstituted benzothiophene, or a substituted orunsubstituted benzofuran. Herein, the substituent for the substitutedalkyl, the substituted aryl, etc., for Z₁ to Z₉ may be specificallyselected from deuterium, a halogen, a cyano, a (C1-C6)alkyl, a(C6-C18)aryl, a 6- to 18-membered heteroaryl or a mono- ordi-(C6-C18)arylamino; and more specifically selected from a (C1-C6)alkylor a mono- or di-(C6-C18)arylamino.

In formula 3, n represents an integer of 0 or 1.

In formula 3, t represents an integer of 0, 1, or 2. Preferably, where tis 0, at least one of Z₁ to Z₉ is a substituted or unsubstituted mono-or di-(C6-C30)arylamino. More preferably, t is an integer of 1 or 2.

Herein, “(C1-C30)alkyl” indicates a linear or branched alkyl having 1 to30, preferably 1 to 20, and more preferably 1 to 10 carbon atoms, andincludes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,tert-butyl, etc. “(C2-C30) alkenyl” indicates a linear or branchedalkenyl having 2 to 30, preferably 2 to 20, and more preferably 2 to 10carbon atoms and includes vinyl, 1-propenyl, 2-propenyl, 1-butenyl,2-butenyl, 3-butenyl, 2-methylbut-2-enyl, etc. “(C2-C30)alkynyl”indicates a linear or branched alkynyl having 2 to 30, preferably 2 to20, and more preferably 2 to 10 carbon atoms and includes ethynyl,1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl,1-methylpent-2-ynyl, etc. “(C3-C30)cycloalkyl” indicates a mono- orpolycyclic hydrocarbon having 3 to 30, preferably 3 to 20, and morepreferably 3 to 7 carbon atoms and includes cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, etc. “3- to 7-membered heterocycloalkyl”indicates a cycloalkyl having 3 to 7, preferably 5 to 7 ring backboneatoms including at least one hetero atom selected from the groupconsisting of B, N, O, S, Si, and P, preferably O, S, and N, andincludes tetrahydrofuran, pyrrolidine, thiolan, tetrahydropyran, etc.Furthermore, “(C6-C30)aryl(ene)” indicates a monocyclic or fused ringradical derived from an aromatic hydrocarbon and having 6 to 30,preferably 6 to 20, and more preferably 6 to 15 ring backbone carbonatoms, and includes phenyl, biphenyl, terphenyl, naphthyl, binaphthyl,phenylnaphthyl, naphthylphenyl, fluorenyl, phenylfluorenyl,benzofluorenyl, dibenzofluorenyl, phenanthrenyl, phenylphenanthrenyl,anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl,chrysenyl, naphthacenyl, fluranthenyl, etc. “3- to 30-memberedheteroaryl” indicates an aryl group having 3 to 30 ring backbone atomsincluding at least one, preferably 1 to 4, hetero atom selected from thegroup consisting of B, N, O, S, Si, and P; may be a monocyclic ring, ora fused ring condensed with at least one benzene ring; may be partiallysaturated; may be one formed by linking at least one heteroaryl or arylgroup to a heteroaryl group via a single bond(s); and includes amonocyclic ring-type heteroaryl such as furyl, thiophenyl, pyrrolyl,imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl,isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl,tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl,etc., and a fused ring-type heteroaryl such as benzofuranyl,benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl,benzoimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl,benzoxazolyl, isoindolyl, indolyl, benzindolyl, indazolyl,benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl,quinoxalinyl, carbazolyl, phenoxazinyl, phenanthridinyl, benzodioxolyl,etc. “Nitrogen-containing 5- to 30-membered heteroaryl” indicates anaryl group having 5 to 30, preferably 5 to 20, and more preferably 5 to15, ring backbone atoms including at least one, preferably 1 to 4,nitrogen atom; may be a monocyclic ring, or a fused ring condensed withat least one benzene ring; may be partially saturated; may be one formedby linking at least one heteroaryl or aryl group to a heteroaryl groupvia a single bond(s); and includes a monocyclic ring-type heteroarylsuch as pyrrolyl, imidazolyl, pyrazolyl, triazinyl, tetrazinyl,triazolyl, tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl,etc., and a fused ring-type heteroaryl such as benzoimidazolyl,isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl,isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl,phenanthridinyl, etc. Furthermore, “halogen” includes F, C1, Br, and I.

Herein, “substituted” in the expression, “substituted or unsubstituted,”means that a hydrogen atom in a certain functional group is replacedwith another atom or group, i.e. a substituent. In the formulae of thepresent disclosure, each of the substituents for the substituted alkyl,the substituted alkenyl, the substituted alkynyl, the substitutedcycloalkyl, the substituted aryl(ene), the substituted heteroaryl, thesubstituted trialkylsilyl, the substituted arylsilyl, the substituteddialkylarylsilyl, the substituted mono- or di-arylamino, the substitutednitrogen-containing heteroaryl in A₁, A₂, L₁, X₁ to X₁₆, Ma, La, and Xato Xh of formulae 1 and 2, each independently, may be at least oneselected from the group consisting of deuterium, a halogen, a cyano, acarboxy, a nitro, a hydroxy, a (C1-C30)alkyl, a halo(C1-C30)alkyl, a(C2-C30)alkenyl, a (C2-C30)alkynyl, a (C1-C30)alkoxy, a(C1-C30)alkylthio, a (C3-C30)cycloalkyl, a (C3-C30)cycloalkenyl, a 3- to7-membered heterocycloalkyl, a (C6-C30)aryloxy, a (C6-C30)arylthio, a 3-to 30-membered heteroaryl unsubstituted or substituted with a(C6-C30)aryl, a (C6-C30)aryl unsubstituted or substituted with a cyano,a 3- to 30-membered heteroaryl or a tri(C6-C30)arylsilyl, atri(C1-C30)alkylsilyl, a tri(C6-C30)arylsilyl, adi(C1-C30)alkyl(C6-C30)arylsilyl, a (C1-C30)alkyldi(C6-C30)arylsilyl, anamino, a mono- or di-(C1-C30)alkylamino, a mono- ordi-(C6-C30)arylamino, a (C1-C30)alkyl(C6-C30)arylamino, a(C1-C30)alkylcarbonyl, a (C1-C30)alkoxycarbonyl, a (C6-C30)arylcarbonyl,a di(C6-C30)arylboronyl, a di(C1-C30)alkylboronyl, a(C1-C30)alkyl(C6-C30)arylboronyl, a (C6-C30)aryl(C1-C30)alkyl, and a(C1-C30)alkyl(C6-C30)aryl; and preferably, a cyano, a (C1-C6)alkyl, a 5-to 15-membered heteroaryl, a (C6-C18)aryl unsubstituted or substitutedwith a cyano, or a tri(C6-C12)arylsilyl, a tri(C6-C12)arylsilyl and a(C1-C6)alkyl(C6-C12)aryl.

In formula 1, triarylsilyl for X₁ to X₁₆ is preferably triphenylsilyl.

The first host compound represented by formula 1 includes the following,but is not limited thereto.

The second host compound represented by formula 2 includes thefollowing, but is not limited thereto.

The hole transport compound represented by formula 3 includes thefollowing, but is not limited thereto.

The organic electroluminescent device of the present disclosurecomprises an anode, a cathode, and an organic layer between the anodeand the cathode, wherein the organic layer comprises one or morelight-emitting layers and one or more hole transport layers; at leastone of the one or more light-emitting layers comprises one or moredopant compounds and two or more host compounds; a first host compoundof the two or more host compounds is represented by formula 1; a secondhost compound is represented by formula 2; and at least one of the oneor more hole transport layers comprises the compound represented byformula 3.

The light-emitting layer indicates a layer from which light is emitted.It is preferable that a doping amount of the dopant compound is lessthan 20 wt % based on the total amount of the host compound and thedopant compound. In the organic electroluminescent device of the presentdisclosure, the weight ratio between the first host material and thesecond host material may be in the range of 1:99 to 99:1, andspecifically 30:70 to 70:30.

In addition to the light-emitting layer and the hole transport layer,the organic layer may further comprise at least one layer selected froma hole injection layer, an electron transport layer, an electroninjection layer, an electron buffering layer, an interlayer, a holeblocking layer, and an electron blocking layer.

The dopant to be comprised in the organic electroluminescent device ofthe present disclosure is preferably at least one phosphorescent dopant.The phosphorescent dopant material for the organic electroluminescentdevice of the present disclosure is not limited, but may be preferablyselected from metallated complex compounds of iridium (Ir), osmium (Os),copper (Cu) or platinum (Pt), more preferably selected fromortho-metallated complex compounds of iridium (Ir), osmium (Os), copper(Cu) or platinum (Pt), and even more preferably ortho-metallated iridiumcomplex compounds. Preferably, the phosphorescent dopant may be selectedfrom the group consisting of compounds represented by the followingformulae 101 to 103.

wherein L is selected from the following structures:

R₁₀₀ represents hydrogen, a substituted or unsubstituted (C1-C30)alkyl,or a substituted or unsubstituted (C3-C30)cycloalkyl; R₁₀₁ to R₁₀₉ andR₁₁₁ to R₁₂₃, each independently, represent hydrogen, deuterium, ahalogen, a (C1-C30)alkyl unsubstituted or substituted with a halogen, acyano, a substituted or unsubstituted (C1-C30)alkoxy or a substituted orunsubstituted (C3-C30)cycloalkyl; R₁₀₆ to R₁₀₉, each independently, maybe linked to an adjacent substituent(s) to form a substituted orunsubstituted 3- to 30-membered, mono- or polycyclic, alicyclic oraromatic ring (e.g., a substituted or unsubstituted fluorene, asubstituted or unsubstituted dibenzothiophene, or a substituted orunsubstituted dibenzofuran); R₁₂₀ to R₁₂₃, each independently, may belinked to an adjacent substituent(s) to form a substituted orunsubstituted 3- to 30-membered, mono- or polycyclic, alicyclic oraromatic ring (e.g., a substituted or unsubstituted quinoline); R₁₂₄ toR₁₂₇, each independently, represent hydrogen, deuterium, a halogen, asubstituted or unsubstituted (C1-C30)alkyl, or a substituted orunsubstituted (C6-C30)aryl; where R₁₂₄, R₁₂₅, R₁₂₆, or R₁₂₇ is aryl, itmay be linked to an adjacent substituent(s) to form a substituted orunsubstituted 3- to 30-membered, mono- or polycyclic, alicyclic oraromatic ring (e.g., a substituted or unsubstituted fluorene, asubstituted or unsubstituted dibenzothiophene, or a substituted orunsubstituted dibenzofuran); R₂₀₁ to R₂₁₁, each independently, representhydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted orsubstituted with a halogen, a substituted or unsubstituted(C3-C30)cycloalkyl, or a substituted or unsubstituted (C6-C30)aryl;R₂₀₈, R₂₀₉, R₂₁₀, or R₂₁₁ may be linked to an adjacent substituent(s) toform a substituted or unsubstituted 3- to 30-membered, mono- orpolycyclic, alicyclic or aromatic ring (e.g., a substituted orunsubstituted fluorene, a substituted or unsubstituted dibenzothiophene,or a substituted or unsubstituted dibenzofuran); r and s, eachindependently, represent an integer of 1 to 3; when r or s is an integerof 2 or more, each of R₁₀₀ may be the same or different; and erepresents an integer of 1 to 3.

Specifically, the phosphorescent dopant material includes the following:

In the organic electroluminescent device of the present disclosure, theorganic layer may further comprise at least one compound selected fromthe group consisting of arylamine-based compounds andstyrylarylamine-based compounds.

In the organic electroluminescent device of the present disclosure, theorganic layer may further comprise at least one metal selected from thegroup consisting of metals of Group 1, metals of Group 2, transitionmetals of the 4^(th) period, transition metals of the 5^(th) period,lanthanides and organic metals of the d-transition elements of thePeriodic Table, or at least one complex compound comprising the metal.

In the organic electroluminescent device of the present disclosure,preferably, at least one layer (hereinafter, “a surface layer”) may beplaced on an inner surface(s) of one or both electrode(s), selected froma chalcogenide layer, a metal halide layer and a metal oxide layer.Specifically, a chalcogenide (includes oxides) layer of silicon oraluminum is preferably placed on an anode surface of anelectroluminescent medium layer, and a metal halide layer or a metaloxide layer is preferably placed on a cathode surface of anelectroluminescent medium layer. Such a surface layer provides operationstability for the organic electroluminescent device. Preferably, thechalcogenide includes SiO_(x) (1≦X≦2), AlO_(x) (1≦X≦1.5), SiON, SiAlON,etc.; the metal halide includes LiF, MgF₂, CaF₂, a rare earth metalfluoride, etc.; and the metal oxide includes Cs₂O, Li₂O, MgO, SrO, BaO,CaO, etc.

In addition to the hole transport layer, a hole injection layer, anelectron blocking layer, or a combination thereof may be disposedbetween the anode and the light-emitting layer. The hole injection layermay be composed of two or more layers in order to lower an energybarrier for injecting holes from the anode to a hole transport layer oran electron blocking layer (or a voltage for injecting a hole). Each ofthe layers may comprise two or more compounds. The electron blockinglayer may be composed of two or more layers.

An electron buffering layer, a hole blocking layer, an electrontransport layer, an electron injection layer, or a combination thereofmay be disposed between the light-emitting layer and the cathode. Theelectron buffering layer may be composed of two or more layers in orderto control the electron injection and improve characteristics ofinterface between the light-emitting layer and the electron injectionlayer. Each of the layers may comprise two or more compounds. The holeblocking layer or electron transport layer may be composed of two ormore layers, and each of the layers may comprise two or more compounds.

In the organic electroluminescent device of the present disclosure, amixed region of an electron transport compound and a reductive dopant,or a mixed region of a hole transport compound and an oxidative dopantmay be placed on at least one surface of a pair of electrodes. In thiscase, the electron transport compound is reduced to an anion, and thusit becomes easier to inject and transport electrons from the mixedregion to an electroluminescent medium. Furthermore, the hole transportcompound is oxidized to a cation, and thus it becomes easier to injectand transport holes from the mixed region to the electroluminescentmedium. Preferably, the oxidative dopant includes various Lewis acidsand acceptor compounds, and the reductive dopant includes alkali metals,alkali metal compounds, alkaline earth metals, rare-earth metals, andmixtures thereof. A reductive dopant layer may be employed as a chargegenerating layer to prepare an electroluminescent device having two ormore light-emitting layers and emitting white light.

In order to form each layer of the organic electroluminescent device ofthe present disclosure, dry film-forming methods such as vacuumevaporation, sputtering, plasma and ion plating methods, or wetfilm-forming methods such as inkjet printing, nozzle printing, slotcoating, spin coating, dip coating, and flow coating methods can beused. Where a layer is formed with the first host compound and thesecond host compound of the present disclosure, they may beco-evaporated or mixture-evaporated.

When using a wet film-forming method, a thin film can be formed bydissolving or diffusing materials forming each layer into any suitablesolvent such as ethanol, chloroform, tetrahydrofuran, dioxane, etc. Thesolvent can be any solvent where the materials forming each layer can bedissolved or diffused, and where there are no problems in film-formationcapability.

In the organic electroluminescent device of the present disclosure, twoor more host compounds for a light-emitting layer may be co-evaporatedor mixture-evaporated. Herein, a co-evaporation indicates a process fortwo or more materials to be deposited as a mixture, by introducing eachof the two or more materials into respective crucible cells, andapplying electric current to the cells for each of the materials to beevaporated. Herein, a mixture-evaporation indicates a process for two ormore materials to be deposited as a mixture, by mixing the two or morematerials in one crucible cell before the deposition, and applyingelectric current to the cell for the mixture to be evaporated.

The organic electroluminescent device of the present disclosure can beused for the manufacture of a display system or a lighting system.

Hereinafter, the preparation method of the device comprising a hostcompound and a hole transport compound of the present disclosure, andthe luminescent properties of the device will be explained in detailwith reference to the following examples.

[Device Examples 1-1 to 1-8] OLED Produced by an Evaporation of the HoleTransport Compound of the Present Disclosure and a Co-Evaporation of aFirst Host Compound and a Second Host Compound of the Present Disclosure

An organic electroluminescent device (OLED) was produced using thelight-emitting material of the present disclosure as follows. Atransparent electrode indium tin oxide (ITO) thin film (10 Ω/sq) on aglass substrate for an OLED (Geomatec) was subjected to an ultrasonicwashing with acetone, ethanol, and distilled water sequentially, and wasthen stored in isopropanol. The ITO substrate was then mounted on asubstrate holder of a vacuum vapor depositing apparatus.N4,N4′-biphenyl-N4,N4′-bis(9-phenyl-9H-carbazol-3-yl)-[1,1′-biphenyl]-4,4′-diamine(HI-1) was introduced into a cell of the vacuum vapor depositingapparatus, and then the pressure in the chamber of the apparatus wascontrolled to 10⁻⁶ torr. Thereafter, an electric current was applied tothe cell to evaporate HI-1, thereby forming a first hole injection layerhaving a thickness of 80 nm on the ITO substrate.1,4,5,8,9,12-hexa-azatriphenylene-hexacarbonitrile (HI-2) was thenintroduced into another cell of the vacuum vapor depositing apparatus,and evaporated by applying electric current to the cell, thereby forminga second hole injection layer having a thickness of 3 nm on the firsthole injection layer.N-([1,1′-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-aminewas introduced into one cell of the vacuum vapor depositing apparatus,and evaporated by applying electric current to the cell, thereby forminga first hole transport layer having a thickness of 10 nm on the secondhole injection layer. A second hole transport compound shown in Table 1below was then introduced into another cell of the vacuum vapordepositing apparatus, and evaporated by applying electric current to thecell, thereby forming a second hole transport layer having a thicknessof 30 nm on the first hole transport layer. As a host material, H1-34 orH1-35, and H2-31 were introduced into two cells of the vacuum vapordepositing apparatus, respectively. A dopant compound D-25 wasintroduced into another cell. The two host compounds were evaporated atthe same rate of 1:1, while the dopant was evaporated at a differentrate from the host compounds, so that the dopant was deposited in adoping amount of 15 wt % based on the total amount of the host anddopant to form a light-emitting layer having a thickness of 40 nm on thehole transport layer.2,4-bis(9,9-dimethyl-9H-fluoren-2-yl)-6-(naphthalen-2-yl)-1,3,5-triazine(ET-1) and lithium quinolate (EI-1) were introduced into two cells ofthe vacuum vapor depositing apparatus, respectively, and evaporated atthe rate of 4:6, thereby forming an electron transport layer having athickness of 35 nm on the light-emitting layer. After depositing lithiumquinolate (EI-1) as an electron injection layer having a thickness of 2nm on the electron transport layer, an Al cathode having a thickness of80 nm was then deposited by another vacuum vapor deposition apparatus onthe electron injection layer.

[Comparative Examples 1-1 and 1-2] OLED Using HTL-A as a Second HoleTransport Compound

OLEDs were produced in the same manner as in Device Examples 1-1 to 1-8,except that HTL-A shown below was used as a second hole transportcompound.

A luminous efficiency, CIE color coordinate, a driving voltage at 1,000nit, and time taken to be reduced from 100% to 85% of the luminance at15,000 nit and a constant current (T85 lifespan) of OLEDs produced abovewere measured. The luminous characteristics of the organicelectroluminescent devices produced in Device Examples 1-1 to 1-8 andComparative Examples 1-1 to 1-2 are shown in Table 1 below.

TABLE 1 Color T85 Device The second hole Voltage Efficiency coordinateLifespan Example No. transport layer Host [V) [cd/A] (x, y) [hr] 1-1H4-11 H1-34:H2-31 3.2 60.0 0.297, 0.658 250 1-2 H4-49 H1-34:H2-31 3.156.6 0.298, 0.658 230 1-3 H4-56 H1-35:H2-31 3.2 58.4 0.299, 0.659 2201-4 H4-1 H1-35:H2-31 3.4 57.6 0.298, 0.658 220 1-5 H4-76 H1-35:H2-31 3.260.4 0.297, 0.659 240 1-6 H4-17 H1-35:H2-31 3.0 61.4 0.295, 0.660 2601-7 H4-9 H1-35:H2-31 3.1 61.2 0.296, 0.660 240 1-8 H4-23 H1-35:H2-31 3.163.6 0.295, 0.660 230 Comparative HTL-A H1-34:H2-31 3.5 51.6 0.301,0.660 40 Example 1-1 Comparative HTL-A H1-35:H2-31 3.5 62.8 0.297, 0.65750 Example 1-2

As confirmed in the Device Examples, the organic electroluminescentdevice of the present disclosure has better lifespan than conventionaldevices by comprising a specific hole transport compound and a pluralityof hosts.

1. An organic electroluminescent device comprising an anode, a cathode,and an organic layer between the anode and the cathode, wherein theorganic layer comprises one or more light-emitting layers and one ormore hole transport layers; at least one of the one or morelight-emitting layers comprises one or more dopant compounds and two ormore host compounds; a first host compound of the two or more hostcompounds is represented by the following formula 1; a second hostcompound is represented by the following formula 2; and at least one ofthe one or more hole transport layers comprises the compound representedby the following formula 3:

wherein A₁ and A₂, each independently, represent a substituted orunsubstituted (C6-C30)aryl, provided that a nitrogen-containingheteroaryl is excluded from the substituent for A₁ and A₂; L₁ representsa single bond or a substituted or unsubstituted (C6-C30)arylene; X₁ toX₁₆, each independently, represent hydrogen, deuterium, a halogen, acyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted orunsubstituted (C2-C30)alkenyl, a substituted or unsubstituted(C2-C30)alkynyl, a substituted or unsubstituted (C3-C30)cycloalkyl, asubstituted or unsubstituted (C6-C60)aryl, a substituted orunsubstituted 3- to 30-membered heteroaryl, a substituted orunsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstitutedtri(C6-C30)arylsilyl, a substituted or unsubstituteddi(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted(C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstitutedmono- or di-(C6-C30)arylamino; or may be linked to an adjacentsubstituent(s) to form a substituted or unsubstituted (C3-C30), mono- orpolycyclic, alicyclic or aromatic ring, whose carbon atom(s) may bereplaced with at least one hetero atom selected from nitrogen, oxygen,and sulfur;

wherein Ma represents a substituted or unsubstituted nitrogen-containing5- to 11-membered heteroaryl; La represents a single bond, or asubstituted or unsubstituted (C6-C30)arylene; Xa to Xh, eachindependently, represent hydrogen, deuterium, a halogen, a cyano, asubstituted or unsubstituted (C1-C30)alkyl, a substituted orunsubstituted (C2-C30)alkenyl, a substituted or unsubstituted(C2-C30)alkynyl, a substituted or unsubstituted (C3-C30)cycloalkyl, asubstituted or unsubstituted (C6-C60)aryl, a substituted orunsubstituted 3- to 30-membered heteroaryl, a substituted orunsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstitutedtri(C6-C30)arylsilyl, a substituted or unsubstituteddi(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted(C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstitutedmono- or di-(C6-C30)arylamino; or may be linked to an adjacentsubstituent(s) to form a substituted or unsubstituted (C3-C30), mono- orpolycyclic, alicyclic or aromatic ring, whose carbon atom(s) may bereplaced with at least one hetero atom selected from nitrogen, oxygen,and sulfur;

wherein A₄ and A₅, each independently, represent a substituted orunsubstituted (C6-C30)aryl; L₃ represents a single bond or a substitutedor unsubstituted (C6-C30)arylene; Z₁ to Z₉, each independently,represent hydrogen, deuterium, a halogen, a cyano, a substituted orunsubstituted (C1-C30)alkyl, a substituted or unsubstituted(C2-C30)alkenyl, a substituted or unsubstituted (C2-C30)alkynyl, asubstituted or unsubstituted (C3-C30)cycloalkyl, a substituted orunsubstituted (C6-C60)aryl, a substituted or unsubstituted 3- to30-membered heteroaryl, a substituted or unsubstitutedtri(C1-C30)alkylsilyl, a substituted or unsubstitutedtri(C6-C30)arylsilyl, a substituted or unsubstituteddi(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted(C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstitutedmono- or di-(C6-C30)arylamino; or may be linked to an adjacentsubstituent(s) to form a substituted or unsubstituted (C3-C30), mono- orpolycyclic, alicyclic or aromatic ring, whose carbon atom(s) may bereplaced with at least one hetero atom selected from nitrogen, oxygen,and sulfur; n represents an integer of 0 or 1; t represents an integerof 0, 1, or 2; and the heteroaryl contains at least one hetero atomselected from B, N, O, S, Si, and P.
 2. The organic electroluminescentdevice according to claim 1, wherein in formula 1, A₁ and A₂, eachindependently, are selected from the group consisting of a substitutedor unsubstituted phenyl, a substituted or unsubstituted biphenyl, asubstituted or unsubstituted terphenyl, a substituted or unsubstitutednaphthyl, a substituted or unsubstituted fluorenyl, a substituted orunsubstituted benzofluorenyl, a substituted or unsubstitutedphenanthrenyl, a substituted or unsubstituted anthracenyl, a substitutedor unsubstituted indenyl, a substituted or unsubstituted triphenylenyl,a substituted or unsubstituted pyrenyl, a substituted or unsubstitutedtetracenyl, a substituted or unsubstituted perylenyl, a substituted orunsubstituted chrysenyl, a substituted or unsubstituted phenylnaphthyl,a substituted or unsubstituted naphthylphenyl, and a substituted orunsubstituted fluoranthenyl.
 3. The organic electroluminescent deviceaccording to claim 1, wherein in formula 1, L₁ represents a single bond,or one selected from the following formulae 9 to
 21.

wherein Xi to Xp, each independently, represent hydrogen, deuterium, ahalogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, asubstituted or unsubstituted (C2-C30)alkenyl, a substituted orunsubstituted (C2-C30)alkynyl, a substituted or unsubstituted(C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C60)aryl, asubstituted or unsubstituted 3- to 30-membered heteroaryl, a substitutedor unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstitutedtri(C6-C30)arylsilyl, a substituted or unsubstituteddi(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted(C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstitutedmono- or di-(C6-C30)arylamino; or may be linked to an adjacentsubstituent(s) to form a substituted or unsubstituted (C3-C30), mono- orpolycyclic, alicyclic or aromatic ring, whose carbon atom(s) may bereplaced with at least one hetero atom selected from nitrogen, oxygen,and sulfur; and

represents a bonding site.
 4. The organic electroluminescent deviceaccording to claim 1, wherein in formula 2, Ma represents a substitutedor unsubstituted monocyclic ring-type heteroaryl selected from the groupconsisting of a substituted or unsubstituted pyrrolyl, a substituted orunsubstituted imidazolyl, a substituted or unsubstituted pyrazolyl, asubstituted or unsubstituted triazinyl, a substituted or unsubstitutedtetrazinyl, a substituted or unsubstituted triazolyl, a substituted orunsubstituted tetrazolyl, a substituted or unsubstituted pyridyl, asubstituted or unsubstituted pyrazinyl, a substituted or unsubstitutedpyrimidinyl, and a substituted or unsubstituted pyridazinyl, or asubstituted or unsubstituted fused ring-type heteroaryl selected fromthe group consisting of a substituted or unsubstituted benzimidazolyl, asubstituted or unsubstituted isoindolyl, a substituted or unsubstitutedindolyl, a substituted or unsubstituted indazolyl, a substituted orunsubstituted benzothiadiazolyl, a substituted or unsubstitutedquinolyl, a substituted or unsubstituted isoquinolyl, a substituted orunsubstituted cinnolinyl, a substituted or unsubstituted quinazolinyl, asubstituted or unsubstituted naphthyridinyl, and a substituted orunsubstituted quinoxalinyl.
 5. The organic electroluminescent deviceaccording to claim 1, wherein in formula 2, La represents a single bond,or one selected from the following formulae 9 to
 21.

wherein Xi to Xp, each independently, represent hydrogen, deuterium, ahalogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, asubstituted or unsubstituted (C2-C30)alkenyl, a substituted orunsubstituted (C2-C30)alkynyl, a substituted or unsubstituted(C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C60)aryl, asubstituted or unsubstituted 3- to 30-membered heteroaryl, a substitutedor unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstitutedtri(C6-C30)arylsilyl, a substituted or unsubstituteddi(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted(C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstitutedmono- or di-(C6-C30)arylamino; or may be linked to an adjacentsubstituent(s) to form a substituted or unsubstituted (C3-C30), mono- orpolycyclic, alicyclic or aromatic ring, whose carbon atom(s) may bereplaced with at least one hetero atom selected from nitrogen, oxygen,and sulfur; and

represents a bonding site.
 6. The organic electroluminescent deviceaccording to claim 1, wherein in formula 2, Xa to Xh, eachindependently, represent hydrogen, a cyano, a (C6-C15)aryl unsubstitutedor substituted with a tri(C6-C10)arylsilyl, or a 10- to 20-memberedheteroaryl unsubstituted or substituted with a (C6-C12)aryl; or may belinked to an adjacent substituent(s) to form a substituted orunsubstituted benzene, a substituted or unsubstituted indole, asubstituted or unsubstituted benzindole, a substituted or unsubstitutedindene, a substituted or unsubstituted benzofuran, or a substituted orunsubstituted benzothiophene.
 7. The organic electroluminescent deviceaccording to claim 1, wherein in formula 3, A₄ and A₅, eachindependently, represent a substituted or unsubstituted (C6-C30)aryl; L₃represents a single bond or a substituted or unsubstituted(C6-C18)arylene; Z₁ to Z₉, each independently, represent hydrogen,deuterium, a halogen, a cyano, a substituted or unsubstituted(C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, asubstituted or unsubstituted 6- to 30-membered heteroaryl, or asubstituted or unsubstituted mono- or di-(C6-C30)arylamino; or one tothree pairs selected from Z₁ and Z₂, Z₂ and Z₃, Z₄ and Z₅, Z₅ and Z₆, Z₇and Z₈, and Z₈ and Z₉, as a pair of adjacent substituents, may form asubstituted or unsubstituted (C3-C30), mono- or polycyclic aromaticring, whose carbon atom(s) may be replaced with one to three heteroatoms selected from nitrogen, oxygen, and sulfur; n represents aninteger of 0 or 1; and t represents an integer of 1 or
 2. 8. The organicelectroluminescent device according to claim 1, wherein in formula 3, A₄and A₅, each independently, is selected from the group consisting of asubstituted or unsubstituted phenyl, a substituted or unsubstitutedbiphenyl, a substituted or unsubstituted terphenyl, a substituted orunsubstituted naphthyl, a substituted or unsubstituted phenanthrenyl, asubstituted or unsubstituted anthracenyl, a substituted or unsubstitutedpyrenyl, a substituted or unsubstituted tetracenyl, a substituted orunsubstituted chrysenyl, a substituted or unsubstituted fluorenyl, asubstituted or unsubstituted benzofluorenyl, a substituted orunsubstituted fluoranthenyl, a substituted or unsubstitutedtriphenylenyl, and a substituted or unsubstituted spirobifluorenyl; andt represents an integer of 1 or
 2. 9. The organic electroluminescentdevice according to claim 1, wherein the compound of formula 1 isselected from the group consisting of:


10. The organic electroluminescent device according to claim 1, whereinthe compound of formula 2 is selected from the group consisting of:


11. The organic electroluminescent device according to claim 1, whereinthe compound of formula 3 is selected from the group consisting of: